<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <form action="https:baidu.com" method="post">
        <input type="text" name="username" value="用户名">
        <br/><input type="password" maxlength="10" placeholder="请输入密码，不要超过10位数">
        <br/><input type="submit" value="提交">
        <br/><p>选择题</p>
        <form action="https:bilibili.com" method="post">
        <br/><label><input type="checkbox" name="hobby" value="male">帅哥</label>
        <br/><label><input type="checkbox" name="hobby" value="male">美女</label>
        <br/><label><input type="checkbox" name="hobby" value="male">外星人</label>
        <br/><input type="submit" value="提交">

        <input type="file"> 
    </form>
    </form>
</body>
</html>